1. Field of the Invention
The present invention relates to devices and techniques for monitoring a computer system. More specifically, the present invention relates to techniques for performing in-situ measurements of rotational vibration in a computer system.
2. Related Art
Rotational vibration (RV) in computer systems, such as servers, can significantly affect reliability. For example, RV can affect the performance of connectors, motors and data storage devices, such as optical drives and hard-disk drives (HDDs). HDDs, in particular, are usually very sensitive to RV, which can cause drastic degradation of input/output-throughput performance. In some cases, such degradation can lead to failure of the entire computer system and, thus, can affect system availability. Consequently, in order to ensure that a computer system continues to operate in the presence of inevitable vibrations, it is important to be able to measure RV.
Unfortunately, when a computer system is fully assembled and powered on, it is often impossible to measure RV non-intrusively, i.e., without altering the mechanical structure of the computer system. This is because the density of components in modern computer systems has increased so that there is often no free space available to accommodate accelerometers to measure RV.
Moreover, removing components to create free space for local RV measurements is typically not a viable solution because such removal can change the measured RV values. For example, while an empty slot may be produced by taking an HDD out of its storage cage (along with the associated mounting brackets and connectors), the mass loading throughout the storage cage will also be changed, which can significantly alter the RV values. In addition, ‘global’ RV measurements, which may be performed by placing accelerometers on the computer-system case, may only provide information about oscillations of the computer-system case, as opposed to specific components of interest.
Hence, there is a need for other techniques to provide in-situ monitoring of RV in components in a computer system.